Power saving, compact, and lightweight liquid crystal displays are now widely used in portable terminal devices such as mobile telephones and PDAs (Personal Digital Assistants). These liquid crystal displays include transmissive and reflective types. From the standpoint of viewability, a transmissive type display in which a backlight is incorporated is now typically employed.
The use of a backlight, however, not only increases power consumption, but also stands in the way of smaller size and lighter weight. Therefore, there exists a need for a reflective liquid crystal display that has good viewability, particularly for portable terminal devices in which small size and light weight are critical and that use a battery as a power source. A known technique for improving the viewability of such a reflective liquid crystal display involves forming unevenness on the reflecting surface of the reflective substrate to improve the reflection characteristics of the reflective substrate. This technique is disclosed in, for example, Japanese Patent Publication No. 2,912,176.
In order to form random unevenness on the reflecting surface of a reflective substrate in this way, pattern data must be generated in which dot patterns, which are to form depressions or protrusions, are randomly distributed. As one example of a method of generating such pattern data, a multiplicity of base coordinates that are regularly distributed horizontally and vertically at a predetermined pitch may be randomly displaced and dot patterns then arranged at each of these randomly displaced coordinates.
However, this simple and random displacement of the base coordinates at which dot patterns are arranged may result in problems such as overlapping of neighboring dot patterns or excessive distance between neighboring dot patterns. Excessive distance between neighboring dot patterns in particular results in a reflecting surface that reflects all incident light, which seriously degrades the reflection characteristics of the reflective substrate.